coolant temperature INFINITI QX56 2009 Factory Workshop Manual

EC-454
< ECU DIAGNOSIS >[VK56DE]
ECM
 When there is an open circuit on MIL circuit, the ECM c
annot warn the driver by lighting up MIL when there
is malfunction on engine control system.
Therefore, when electrical controlled throttle and pa rt of ECM related diagnoses are continuously detected
as NG for 5 trips, ECM warns the driver that engi ne control system malfunctions and MIL circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnos es except MIL circuit are detected and demands the
driver to repair the malfunction.
DTC No. Detected items Engine operating condition in fail-safe mode
P0102
P0103 Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118 Engine coolant tempera-
ture sensor circuit Engine coolant temperature will be determined by ECM based on the following condition.
CONSULT-IIl displays the engine coolant temperature decided by ECM.
Condition Engine coolant temperature decided
(CONSULT-IIl display)
Just as ignition switch is turned ON
or START 40
°C (104 °F)
Approx 4 minutes or more after en-
gine starting. 80
°C (176 °F)
Except as shown above 40 - 80
°C (104 - 176 °F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling
fan operates while engine is running.
P0122
P0123
P0222
P0223
P2135 Throttle position sensor The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
P0643 Sensor power supply ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2100
P2103 Throttle control motor relay ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2101 Electric throttle control function ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2118 Throttle control motor ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2119 Electric thro ttle control ac-
tuator (When electric throttle control actuator does not function properly due to the return spring
malfunction:)
ECM controls the electric throttle actuator by regulating the throttle opening around the
idle position. The engine speed will not rise more than 2,000 rpm.
(When throttle valve opening angle in fail-safe mode is not in specified range:)
ECM controls the electric throttle control actuator by regulating the throttle opening to 20
degrees or less.
(When ECM detects the throttle valve is stuck open:)
While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops, the
engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or
more.
P2122
P2123
P2127
P2128
P2138 Accelerator pedal position
sensor
The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut
Revision: December 20092009 QX56

ECM
EC-455
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DTC Inspection Priority ChartINFOID:0000000003771736
If some DTCs are displayed at the same time, per
form inspections one by one based on the following priority
chart.
NOTE:
 If DTC U1000 and/or U1001 is displayed with other DTC, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-86
.
 If DTC P0607 is displayed with ot her DTC, first perform the trouble diagnosis for DTC P0607. Refer to
EC-284
.
Priority Detected items (DTC)
1  U1000 U1001 CAN communication line  P0101 P0102 P0103 Mass air flow sensor
 P0112 P0113 P0127 Intake air temperature sensor
 P0116 P0117 P0118 P0125 Engine coolant temperature sensor
 P0122 P0123 P0222 P0223 P1225 P1226 P2135 Throttle position sensor
 P0128 Thermostat function
 P0181 P0182 P0183 Fuel tank temperature sensor
 P0327 P0328 P0332 P0333 Knock sensor
 P0335 Crankshaft position sensor (POS)
 P0340 Camshaft posi tion sensor (PHASE)
 P0460 P0461 P0462 P0463 Fuel level sensor
 P0500 Vehicle speed sensor
 P0605 P0607 ECM
 P0643 Sensor power supply
 P0700 TCM
 P0705 Transmission range switch
 P0850 Park/neutral position (PNP) switch
 P1550 P1551 P1552 P1553 P1554 Battery current sensor
 P1610 - P1615 NATS
 P2122 P2123 P2127 P2128 P2138 Accelerator pedal position sensor
Revision: December 20092009 QX56

ECM
EC-461
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Procedures for clearing the DTC and the 1st trip DT
C from the ECM memory are described in "HOW TO
ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION".
For malfunctions in which 1st trip DTCs are displa yed, refer to "EMISSION-RELATED DIAGNOSTIC INFOR-
MATION ITEMS". These items are required by legal r egulations to continuously monitor the system/compo-
nent. In addition, the items monitored non-cont inuously are also displayed on CONSULT-III.
1st trip DTC is specified in Service $07 of SAE J1979. 1st trip DTC detection occurs without lighting up the MIL
and therefore does not warn the driver of a malfunction. However, 1st trip DTC detection will not prevent the
vehicle from being tested, for example during Inspection/Maintenance (I/M) tests.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in Work Flow procedure Step 2, refer to EC-8, "Trouble Diagnosis Introduction"
. Then per-
form DTC Confirmation Procedure or Overall Function Che ck to try to duplicate the malfunction. If the mal-
function is duplicated, the item requires repair.
How to Read DTC and 1st Trip DTC
DTC and 1st trip DTC can be read by the following methods.
With CONSULT-III
With GST
CONSULT-III or GST (Generic Scan Tool ) Examples: P0340, P0850, P1148, etc.
These DTCs are prescribed by SAE J2012.
(CONSULT-III also displays the malfunctioning component or system.)
No Tools
The number of blinks of the MIL in the Diagnostic Test Mode II (Self-Diagnostic Results) indicates the DTC.
Example: 0340, 0850, 1148, etc.
These DTCs are controlled by NISSAN.
 1st trip DTC No. is the same as DTC No.
 Output of a DTC indicates a malfunc tion. However, GST or the Diagnostic Test Mode II do not indi-
cate whether the malfunction is stil l occurring or has occurred in the past and has returned to nor-
mal. CONSULT-III can identify malfunction status as shown below. Therefore, using CONSULT-III (if
available) is recommended.
DTC or 1st trip DTC of a malfunction is display ed in SELF-DIAGNOSTIC RESULTS mode of CONSULT-III.
Time data indicates how many times the vehicle was driven after the last detection of a DTC.
If the DTC is being detected currently, the time data will be [0].
If a 1st trip DTC is stored in the ECM, the time data will be [1t].
FREEZE FRAME DATA AND 1ST TRIP FREEZE FRAME DATA
The ECM records the driving conditions such as fuel system status, calculated load value, engine coolant tem-
perature, short term fuel trim, long term fuel trim, engi ne speed, vehicle speed, absolute throttle position, base
fuel schedule and intake air temperature at the moment a malfunction is detected.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data.
The data, stored together with the DTC data, are ca lled freeze frame data and displayed on CONSULT-III or
GST. The 1st trip freeze frame data can only be displa yed on the CONSULT-III screen, not on the GST. For
details, see EC-63, "CONSULT-III Function (ENGINE)"
.
Only one set of freeze frame data (either 1st trip freez e frame data or freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM me mory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
For example, the EGR malfunction (P riority: 2) was detected and the freeze frame data was stored in the 2nd
trip. After that when the misfire (Priority: 1) is detected in another trip, the freeze frame data will be updated
from the EGR malfunction to the misfire. The 1st trip freeze frame data is updated each time a different mal-
function is detected. There is no priority for 1st tr ip freeze frame data. However, once freeze frame data is
stored in the ECM memory, 1st trip freeze data is no longer stored (because only one freeze frame data or 1st
trip freeze frame data can be stored in the ECM). If fr eeze frame data is stored in the ECM memory and freeze
Priority Items
1 Freeze frame data Misfire — DTC: P0300 - P0308
Fuel Injection System Function — DTC: P0171, P0172, P0174, P0175
2 Except the above items (Includes A/T related items)
3 1st trip freeze frame data
Revision: December 20092009 QX56

ECM
EC-467
< ECU DIAGNOSIS > [VK56DE]
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 Sea level
 Flat road
 Ambient air temperature: 20 - 30
°C (68 - 86 °F)
 Diagnosis is performed as quickly as possible under normal conditions.
Under different conditions [For example: ambient air temperature other than 20 - 30 °C (68 - 86 °F)], diagno-
sis may also be performed.
Pattern 1:
 The engine is started at the engine coolant temperature of −10 to 35 °C (14 to 95 °F)
(where the voltage between the ECM terminal 73 and ground is 3.0 - 4.3V).
 The engine must be operated at id le speed until the engine coolant temperature is greater than 70 °C
(158 °F) (where the voltage between the ECM te rminal 73 and ground is lower than 1.4V).
 The engine is started at the fuel tank temperature of warmer than 0 °C (32 °F) (where the voltage
between the ECM terminal 107 and ground is less than 4.1V).
Pattern 2:
 When steady-state driving is performed again even afte r it is interrupted, each diagnosis can be conducted.
In this case, the time required for diagnosis may be extended.
Pattern 3:
 Operate vehicle following the driving pattern shown in the figure.
 Release the accelerator pedal during decelerating vehicle speed from 90 km/h (56 MPH) to 0 km/h (0 MPH).
Pattern 4:
 The accelerator pedal must be held very steady during steady- state driving.
 If the accelerator pedal is moved, the test must be conducted all over again.
*1: Depress the accelerator pedal until vehicle speed is 90 km/h (56
MPH), then release the accelerator pedal and keep it released for
more than 10 seconds. Depress the accelerator pedal until vehicle
speed is 90 km/h (56 MPH) again.
*2: Checking the vehicle speed with GST is advised.
Suggested Transmi ssion Gear Position
Set the selector lever in the D positi on with the overdrive switch turned ON.
TEST VALUE AND TEST LIMIT
The following is the information specified in Service $06 of SAE J1979.
The test value is a parameter used to determine whether a system/circuit diagnostic test is OK or NG while
being monitored by the ECM during self-diagnosis. The test limit is a reference value which is specified as the
maximum or minimum value and is compared with the test value being monitored.
These data (test value and test limit) are specified by On Boad Monitor ID(OBDMID), Test ID (TID), Unit and
Scaling ID and can be displayed on the GST screen.
The items of the test value and test limit will be disp layed with GST screen which items are provided by the
ECM. (eg., if the bank 2 is not applied on this v ehicle, only the items of the bank 1 is displayed)
PBIB2244E
Revision: December 20092009 QX56

EC-476
< SYMPTOM DIAGNOSIS >[VK56DE]
ENGINE CONTROL SYSTEM SYMPTOMS
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
SYSTEM — ENGINE MECHANICAL & OTHER
Mass air flow sensor circuit
1
12 2
222 2 EC-103,
EC-109
Engine coolant temperature sensor circuit
333
EC-120,
EC-128
Air fuel ratio (A/F ) sensor 1 circuit EC-136
,
EC-140
,
EC-143
,
EC-146
,
EC-377

Throttle position sensor circuit 22EC-124
,
EC-185
,
EC-302
,
EC-304
,
EC-369
Accelerator pedal position sensor circuit 3 2 1 EC-280
,
EC-362
,
EC-365
,
EC-373
Knock sensor circuit 2 3 EC-195
Crankshaft position sensor (POS) circuit 2 2EC-198
Camshaft position sensor (PHASE) circuit 3 2 EC-202
Vehicle speed signal circuit 2 3 3 3 EC-271
Power steering pressure sensor circuit 2 3 3 EC-277
ECM 22333333333 EC-280,
EC-282
Intake valve timing control solenoid valve cir-
cuit 32 13223 3
EC-100
Transmission range signal circuit 3 3 3 3 3 EC-288
Refrigerant pressure sensor circuit 2 3 3 4EC-416
Electrical load signal circuit 3EC-390
Air conditioner circuit 223333333 3 2HAC-25
ABS actuator and electric unit (control unit) 4 BRC-37
SYMPTOM
Refer-
ence page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Revision: December 20092009 QX56

EC-478
< SYMPTOM DIAGNOSIS >[VK56DE]
ENGINE CONTROL SYSTEM SYMPTOMS
1 - 6: The numbers refer to the order of inspection.Exhaust Exhaust manifold/Tube/Muffler/
Gasket 55555 55 5 EM-30
,
EX-
5Three way catalyst
Lubrica-
tion Oil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 5 EM-33
,
LU-
14 , LU-11 ,
LU-12
Oil level (Low)/Filthy oil LU-8, "In-spection"
Cooling Radiator/Hose/Radiator filler cap
55555 55 45 CO-15
Thermostat 5
CO-22
Water pumpCO-20
Water galleryCO-6
Cooling fan 5CO-18,
CO-
19
Coolant level (Low)/Contaminat-
ed coolant 5
CO-10
IVIS (INFINITI Vehicle Immobilizer System —
NATS) 11
SEC-6
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Revision: December 20092009 QX56

NORMAL OPERATING CONDITIONEC-479
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NORMAL OPERATING CONDITION
Fuel Cut Control (at No
Load and High Engine Speed)INFOID:0000000003771740
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
If the engine speed is above 1,800 rpm under no load (for example, the shift position is neutral and engine
speed over is 1,800 rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies
based on engine speed.
Fuel cut will be operated until the engine speed reaches 1,500 rpm, then fuel cut will be cancelled.
NOTE:
This function is different from deceleration control listed under EC-28, "System Description"
.
Sensor Input signal to ECM ECM function Actuator
TCM Neutral position
Fuel cut control Fuel injector
Accelerator pedal position sensor Accelerator pedal position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)
Engine speed
Wheel sensor Vehicle speed*
Revision: December 20092009 QX56

SERVICE DATA AND SPECIFICATIONS (SDS)
EC-495
< SERVICE DATA AND SPECIFICATIONS (SDS) [VK56DE]
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SERVICE DATA AND SPECIFICATIONS (SDS)
SERVICE DATA AND SPECIFICATIONS (SDS)
Fuel PressureINFOID:0000000003771755
Idle Speed and Ignition TimingINFOID:0000000003771756
*: Under the following conditions:
 Air conditioner switch: OFF
 Electric load: OFF (Lights and heater fan)
 Steering wheel: Kept in straight-ahead position
Calculated Load ValueINFOID:0000000003771757
Mass Air Flow SensorINFOID:0000000003771758
*: Engine is warmed up to normal operating temperature and running under no load.
Intake Air Temperature SensorINFOID:0000000003771759
Engine Coolant Temperature SensorINFOID:0000000003771760
A/F Sensor 1 HeaterINFOID:0000000003771761
Fuel pressure at idling kPa (kg/cm2, psi)
Approximately 350 (3.57, 51)
Target idle speed No-load* (in P or N position) 650
±50 rpm
Air conditioner: ON In P or N position 700 rpm or more
Ignition timing In P or N position 15 ° ± 5 ° BTDC
Condition Calculated load value % (Using CONSULT-IIl or GST)
At idle 14.0 - 33.0
At 2,500 rpm 12.0 - 25.0
Supply voltage Battery voltage (11 - 14V)
Output voltage at idle 1.0 - 1.3V*
Mass air flow (Using CONSULT-IIl or GST) 3.0 - 9.0 g·m/sec at idle*
9.0 - 28.0 g·m/sec at 2,500 rpm*
Temperature °C ( °F) Resistance k Ω
25 (77) 1.800 - 2.200
Temperature °C ( °F) Resistance k Ω
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
Resistance [at 25°C (77 °F)] 1.98 - 2.66 Ω
Revision: December 20092009 QX56

EM-68
< ON-VEHICLE REPAIR >
CYLINDER HEAD
CYLINDER HEAD
Exploded ViewINFOID:0000000005885894
Removal and InstallationINFOID:0000000005885895
REMOVAL
1. Remove the engine assembly from the vehicle. Refer to EM-78, "Removal and Installation".
2. Remove the following components and related parts: • Drive belt auto tensioner and idler pulley. Refer to EM-14, "
Drive Belt Auto Tensioner and Idler Pulley".
• Generator assembly and bracket. Refer to CHG-20, "
Removal and Installation".
• Thermostat housing and hose. Refer to CO-22, "
Removal and Installation".
• Oil pan and oil strainer. Refer to EM-33, "
Removal and Installation".
• Fuel tube and fuel injector assembly. Refer to EM-40, "
Removal and Installation".
• Intake manifold. Refer to EM-26, "
Removal and Installation".
• Rocker cover. Refer to EM-38, "
Removal and Installation".
3. Remove the crankshaft pulley, front cover, oil pump, and timing chain. Refer to EM-45, "
Removal and
Installation".
4. Remove the camshaft sprockets and camshafts. Refer to EM-53, "
Removal and Installation".
5. Remove the cylinder head bolts in reverse of order shown.
6. Remove the cylinder heads.
INSPECTION AFTER REMOVAL
Cylinder Head Bolts Diameter
1. Harness bracket 2. Engine coolant temperature sensor 3. Washer
4. Cylinder head gasket (LH) 5. Cylinder head (RH) 6. Cylinder head bolt
7. Cylinder head gasket (RH) 8. Cylinder head (LH)
KBIA2528E
PBIC0068E
Revision: December 20092009 QX56

IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
EXL-121
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IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE
ROOM)
Reference ValueINFOID:0000000004215514
VALUES ON THE DIAGNOSIS TOOL
Monitor Item ConditionValue/Status
MOTOR FAN REQ Engine idle speed Changes depending on engine
coolant temperature, air conditioner
operation status, vehicle speed,
etc.0 - 100 %
A/C COMP REQ A/C switch OFF
OFF
A/C switch ON ON
TA I L & C L R R E Q Lighting switch OFF
OFF
Lighting switch 1ST, 2ND, HI or AUTO (Light is illuminated) ON
HL LO REQ Lighting switch OFF
OFF
Lighting switch 2ND HI or AUTO (Light is illuminated) ON
HL HI REQ Lighting switch OFF
OFF
Lighting switch HI ON
FR FOG REQ Lighting switch 2ND or AUTO (Light
is illuminated) Front fog lamp switch OFF OFF
• Front fog lamp switch ON
• Daytime light activated (Canada
only) ON
HL WASHER REQ NOTE:
This item is displayed, but cannot be monitored.
OFF
FR WIP REQ Ignition switch ON Front wiper switch OFF
STOP
Front wiper switch INT 1LOW
Front wiper switch LO LOW
Front wiper switch HI HI
WIP AUTO STOP Ignition switch ON Front wiper stop position
STOP P
Any position other than front wiper
stop position ACT P
WIP PROT Ignition switch ON Front wiper operates normally OFF
Front wiper stops at fail-safe opera-
tion
BLOCK
ST RLY REQ Ignition switch OFF or ACC
OFF
Ignition switch START ON
IGN RLY Ignition switch OFF or ACC
OFF
Ignition switch ON ON
RR DEF REQ Rear defogger switch OFF
OFF
Rear defogger switch ON ON
OIL P SW Ignition switch OFF, ACC or engine running
OPEN
Ignition switch ON CLOSE
DTRL REQ Daytime light system requested OFF with CONSULT-III.
OFF
Daytime light system reques ted ON with CONSULT-III. ON
HOOD SW Hood closed.
OFF
Hood open. ON
Revision: December 20092009 QX56